Here is the link to Opa's roll out box thread. I agree that once a chicken starts eating unbroken eggs, it is almost impossible to get her to stop. If you are not sure who it is, separate each hen one at a time, anyone who eats her own eggs is going to be your culprit(s).
https://www.backyardchickens.com/a/rollout-nests
https://www.backyardchickens.com/a/rollout-nests